Vì \(\left(2x+3\right)^2=\left[x-\left(-7\right)\right]\)
\(\Rightarrow2x+3=x+7\) hoặc \(2x+3=-x-7\)
Với \(2x+3=x+7\)
\(\Rightarrow2x-x=-3+7\)
\(\Rightarrow x=4\) (\(t\)/\(m\))
Với \(2x+3=-x-7\)
\(\Rightarrow2x+x=-3-7\)
\(\Rightarrow3x=-10\)
\(\Rightarrow x=\frac{-10}{3}\) (\(t\)/\(m\))
Vậy \(x=\left[\begin{matrix}4\\\frac{-10}{3}\end{matrix}\right.\).